Paul died of leukemia Feb. 12, 2006, at his home in Cupertino, Calif.
He was born in Washington, D.C., and attended high school in Wyomissing, Pa. At Princeton, Paul majored in chemical engineering, and was a member of the Glee Club and Elm Club.
Paul received a doctorate in chemical engineering from Cornell University in 1966. After teaching at two Chilean universities and working in industry, he developed an interest in environmental issues and devoted the rest of his professional life to this field.
Paul earned a master's in 1971 in the Honors Cooperative Program of the Stanford School of Engineering and advanced to the rank of full professor at Stanford. While there, he directed a landmark field study to evaluate the potential for reclaiming wastewater from the city of Palo Alto by using advanced treatment processes followed by injection and storage in the aquifer below the San Francisco Bay wetlands.
The author of more than 200 publications, Paul was a member of the Swiss Academy of Sciences and the National Academy of Engineering, and received numerous other professional honors.
Paul's wife of 40 years, Inge; his children, Nina, Christopher, and Sebastian; and nine grandchildren survive him. The class extends sympathy to his family and friends.